1. Field of the Invention
This invention relates to an electronic security card and to a system for authenticating ownership of the card and, more particularly, to such a security card including logic circuitry adapted to provide an output signal if input signals to the circuitry are in a preselected sequence and which is deactivated if the input signals are not in the predetermined sequence.
2. Description of the Prior Art
Credit cards have become a popular and widely used technique for purchasing goods and services. A major problem, however, resides in the use of credit cards or any other security cards by unauthorized persons. The prior art is replete with credit or security cards and systems for authenticating the cards.
Examples of authenticating systems and security cards are found in the following U.S. Pat. Nos. 3,221,304, entitled "Electronic Identification System Employing a Data Bearing Identification Card," by O. C. Enikeieff et al.; 3,401,830, entitled "Vending Machine for Credit Card Purchasing," by H. A. Mathews; 3,513,298, entitled "High Security Credit Card System," by J. B. Riddle et al.; 3,697,729, entitled "Dispensing System and Security Card for Use Therewith," by Edwards et al.; 3,719,804, entitled "Permanent Information Store," by D. A. Illing; 3,740,530, entitled "Apparatus and Method for Verification of a Credit Card," by Hoffer et al.; 3,750,828, entitled "Access-Control Equipment and Item Dispensing Systems Including Such Equipment," by G. E. P. Constable.
However, in the authenticating systems disclosed in the prior art the security cards contain a code which is read by a reader and compared to a code which is inserted by the person using the card. Accordingly, the cards are passive devices and their codes may easily be determined.